全 文 ：植 物 分 类 学 报 44 (3): 286–295(2006) doi:10.1360/aps040169
Acta Phytotaxonomica Sinica http://www.plantsystematics.com
———————————
Received: 16 December 2004 Accepted: 28 July 2005
Supported by the National Natural Science Foundation of China, Grant No. 30170063.
* Author for correspondence. E-mail: jbwang@whu.edu.cn; Tel.: 027-68752213; Fax: 027-68752213.
Genomic evolutionary changes in Aegilops allopolyploids
revealed by ISSR markers
GONG Han-Yu LIU Ai-Hua WANG Jian-Bo*
(Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Sciences, Wuhan University,
Wuhan 430072, China)
Abstract Genomic evolutions were characterized by 31 ISSR (inter-simple sequence repeat)
primers among 23 species in the genus Aegilops. The results indicate that the genome
constituents of allopolyploid species had changed greatly through evolution compared with
their ancestral diploid species. Genome U showed little alterations in U-containing
allopolyploids, while others had undergone changes after allopolyploidization. In addition,
genome U also displayed strong assimilation effect when it coexisted with other genomes, and
the other genomes changed to varying degrees. The evolutionary changes of these genomes
were discussed.
Key words Aegilops, allopolyploid, genomic evolutionary change, ISSR.
Polyploidy is an important process in the evolution of higher plants, and probably as
many as 70% of angiosperms are polyploids (Masterson, 1994). Many important crop plants,
including wheat, oat, coffee, potato, canola, soybean, sugarcane, tobacco and cotton are
polyploids (Liu & Wendel, 2002). The merger of two divergent genomes through
allopolyploidization is a prominent means by which new lineages of plant species originate
(Leitch & Bennett, 1997). Recent studies in several model plant systems have shown that
allopolyploid formation may be associated with rapid and extensive genomic changes
(Feldman et al., 1997; Liu et al., 1999). The newly cohabiting genomes are no longer evolving
independently, but instead interact extensively through a variety of molecular genetic
mechanisms, such as homologous recombination or other interactions that lead to
inter-genomic exchange of chromosome segments (Parokonny & Kenton, 1995),
inter-genomic concerted evolution of divergent sequences (Elder & Turner, 1995; Volkov et
al., 1999), and inter-genic, inter-genomic recombination or gene conversion (Zwierzykowski
et al., 1998). Little is known about the genetic and functional consequences of uniting two
divergent genetic systems into a common nucleus in only one of the two parental cytoplasms
(Wendel, 2000).
In this study, ISSR (inter-simple sequence repeat) technique was used to reveal genomic
evolutionary changes in polyploids. By using single simple sequence repeat (SSR)-containing
primers, ISSR analysis applies the polymerase chain reaction (PCR) to the amplification of
regions between adjacent and inversely oriented microsatellites (Zietjiewicz et al., 1994). This
technique can be used for any species that contains sufficient distribution of SSR motifs, and
has the advantage that genomic sequence data are not required (Gupta et al., 1994). Primers
used in ISSR analysis can be designed based on any of the SSR motifs (di-, tri-, tetra- or
penta-nucleotides) found at microsatellite loci, and the sequence between two binding sites in
opposite orientation within a suitable distance is amplified. Insertions/deletions within this
No. 3 GONG Han-Yu et al.：Genomic evolutionary changes in Aegilops allopolyploids 287
region, as well as losses/gains of binding sites are detected as band polymorphism (Yang et
al., 1996). ISSR markers are usually complementary to dinucleotide simple sequence repeat
motifs, and are abundant in genomic DNA, but they also contain an “anchor” oligo, usually
one to three bases in length, to ensure the primer anneals to either the 5′ or 3′ end of the SSR
(Charters et al., 1996). ISSR has been proven to be valuable for fingerprinting-studies in
maize (Kantety et al., 1995), oilseed (Charters et al., 1996), citrus (Fang et al., 1997), potato
(Prevost & Wilkinson, 1999), rice (Blair et al., 1999) and sweet potato (Huang & Sun, 2000).
It can shed new light on evolution of different types of genomes in polyploids in Aegilops L.
The genus Aegilops, a polyploid complex, is a useful model plant system for studying
genomic changes. It is distributed in the Mediterranean region and Western and Central Asia
(van Slageren, 1994). In this study, twenty-three species were selected for ISSR analysis, and
they differed in their ploidy level (diploid, tetraploid and hexaploid) and genome types (U, D,
M, N, S and C). The objective of the research was to characterize evolutionary genomic
changes of different types of genomes in Aegilops polyploid complex.
1 Material and methods
1.1 Plant materials
The scientific names, genome constituents, ploidy levels and sources of the twenty-three
Aegilops species used are listed in Table 1.


Table 1 Materials used in this study
No. Species Genome Ploidy level Source 1)
01 Aegilops bicornis Jaub. & Spach SbSb 2x ICGRAe4
02 Ae. longissima Schweinf., Muschl. & Eiq SlSl 2x ICGRAe154
03 Ae. speltoides Tausch SS 2x ICGRAe49
04 Ae. searsii M. Fieldman & M. Kislev SsSs 2x KU4-6
05 Ae. sharonensis Eiq SshSsh 2x ICGRAe29
06 Ae. tauschii Coss. DD 2x ICGRAe37
07 Ae. markgrafii (Greuter) K. Hammer CC 2x ICGRY45
08 Ae. umbellulata Zhuk. UU 2x ICGRY139
09 Ae. uniaristata Vis NN 2x KU19-3
10 Ae. comosa Sibth. & Sm. MM 2x ICGRY258
11 Ae. heldreichii Holzm. ex Nyman MhMh 2x KU18-2
12 Ae. crassa Boiss. DDMM 4x ICGRY229
13 Ae. ventricosa Tausch DDNN 4x ICGRY159
14 Ae. cylindrica Host. DDCC 4x ICGRY9
15 Ae. triuncialis L. UUCC 4x ICGRY112
16 Ae. peregrina Eiq UUSS 4x ICGRY88
17 Ae. kotschyi Boiss. UUSS 4x ICGRAe19
18 Ae. columnaris Zhuk. UUMM 4x ICGRAe10
19 Ae. biuncialis Vis UUMM 4x ICGRAe52
20 Ae. ovata L. UUMM 4x ICGRY77
21 Ae. triaristata Willd. UUMMNN 6x ICGRAe58
22 Ae. juvenalis Eiq DDMMUU 6x ICGRAe16
23 Ae. vavilovii (Zhuk.) Chennav. DDMMSS 6x KU21-1
1) KU: Plant Germ-plasm Institute, Faculty of Agriculture, Kyoto University, Japan；ICGR: Institute of Crop Germ-plasm
Resources, Chinese Academy of Agricultural Sciences.



Acta Phytotaxonomica Sinica Vol. 44 288
1.2 DNA extraction and ISSR fingerprinting
Fifteen seedlings from each species were selected randomly for DNA extraction.
Genomic DNA was isolated from 15 g mixed young fresh leaves (1 g leaves per seedling),
using the CTAB procedure of Doyle and Doyle (1987). Thirty-one selected ISSR primers,
between 17-mers to 18-mers (Table 2), from primer set No. 9 (Biotechnology Laboratory,
University of British Columbia, UBC) were used for PCR amplification reactions. The
amplification was carried out in a 25 µL reaction volume containing 1×104 µmol/L Tris-HCl
(pH 8.3), 5×104 µmol/L KCl, 0.001% gelatin, 1.3×103 µmol/L MgCl2, 0.5 µmol/L primer,
0.3×103 µmol/L each dNTP, 4.5×10–2 µg genomic DNA, 1 U Taq DNA polymerase
(Promega). The reaction mix (25 µL) was overlaid with 50 µL mineral oil (Sigma), and PCR
was performed on a MJ Research PTC-100 Thermocycler. Initial denaturation was for 5 min
at 94 ℃; followed by 45 cycles of 1 min at 94 ℃, 1 min at 44 ℃, and 2 min at 72 ℃; with
a final 10 min extension at 72 ℃. The amplification products were size-separated by standard
horizontal electrophoresis in 2% (M/V) agarose and stained with ethidium bromide. The gels
were viewed and photographed by Bio Imaging Systems (Syngene, GeneGenius). PCR
amplifications were repeated twice with each of the primers analyzed in order to test the
reproducibility of the DNA profiles, and only the robust and repeatable bands were scored.

Table 2 ISSR primers and their sequences
B=C, G or T; R=A or G; Y=C or T; H=A, C or T; V=A, C or G
Primer No. (UBC) Sequence (5′–3′) Primer No. (UBC) Sequence (5′–3′)
807 (AG)8T 844 (CT)8RC
808 (AG)8C 847 (CA)8RC
809 (AG)8G 848 (CA)8RG
810 (GA)8 T 849 (GT)8YA
811 (GA)8 C 850 (GT)8YC
813 (CT)8 T 853 (TC)8RT
822 (TC)8A 855 (AC)8YT
825 (AC)8T 856 (AC)8 YA
827 (AC)8G 857 (AC)8YG
834 (AG)8YT 860 (TG)8RA
835 (AG)8YC 884 HBH (AG)7
836 (AG)8Y A 888 BDB (CA)7
840 (GA)8YT 889 DBD (AC)7
841 (GA)8YC 891 HVH (TG)7
842 (GA)8YG 898 (CA)6RY
899 (CA)6RG


1.3 Data analysis
ISSR marker bands were scored as present (1) or absent (0), and the data obtained were
used in a rectangular matrix (detailed information are available upon request). A binary
matrix was constructed based on records of the 288 bands generated from the 31 primers
used. The matrix was then used as input for SIMQUAL module of the NTSYS-pc software
(Rohlf, 1992) with the similarity coefficient set to Dice. Clustering and dendrogram
construction were performed with the SAHN feature of the program by the unweighted
pair-group method with arithmetic average UPGMA (unweighted pair-group method using
arithmetic averages).
No. 3 GONG Han-Yu et al.：Genomic evolutionary changes in Aegilops allopolyploids 289
2 Results
2. 1 Primer selection


Of the 64 potential ISSR primers which could be chosen from, thirty-one were selected
by the appropriate PCR amplification reactions (Table 2). A total of 288 bands were produced
by the 31 primers used, and the number of bands produced by individual primers was in the
range of 5 to 14 with an average frequency of 9.3 bands per primer. Of the 288 bands, 97.22%
(280 bands) were polymorphic. Figure 1 shows the amplification profiles of ISSR primer
UBC-840, and served as an example.

M 1 3 2 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 21 20 19 22 23



2000 bp→

1000 bp→
750 bp→
500 bp→


Fig. 1. Inter-simple sequence repeat (ISSR) banding profile obtained on 2% agarose gel for the 23 Aegilops accessions
with UBC primer 840. The accession numbers are listed in Table 1. M=molecular size marker (DL 2000, Takara).


2. 2 Genetic similarities
The genetic similarity indexes for the 23 accessions were obtained based on the ISSR
data (Table 3). The calculated genetic similarity index between Ae. bicornis (genome Sb) and
Ae. tauschii (D) was 0.7273, which suggested that their genomic constituents were very
similar. Analogous results were obtained between Ae. umbellulata (U) and Ae. comosa (M),
Ae. longissima (Sl) and Ae. searsii (Ss), Ae. speltoides (S) and Ae. sharonensis (Ssh).
Compared with their ancestral diploid genomes, the genetic similarity index between Ae.
tr is (UC) and Ae. umbellulata (U) was 0.6842, which was higher than that between Ae.
tri s (UC) and Ae. markgrafii (C). Once again, analogous results were observed
b Ae. peregrina (US), Ae. kotschyi (US), Ae. columnaris (UM), Ae. biuncialis (UM),
A a (UM), Ae. triaristata (UMN), Ae. juvenalis (DMU) and Ae. umbellulata (U),
re ely. These data indicate that the genomic constituents of polyploid genomes were
v
u
n
s
(T
(0
c
(0
2
2
A
ce. ovat
spectivetween e
n
u
p
r
.
)
e
oiuncial uncialiry similar to that of Ae. umbellulata (U); in other words, the U genome was practically
changed while other genomes were altered greatly when they coexisted in the same
cleus.
In addition, the varied degrees of differentiation of genome D in D-containing polyploid
ecies were observed according to their genetic similarity indexes with Ae. tauschii (D)
able 3). A few noteworthy points: (1) Ae. cylindrica (DC) (0.6533) and Ae. vavilovii (DMS)
.6073), indicating a slightly modified D genome; (2) Ae. juvenalis (DMU) (0.5803) and Ae.
assa (DM) (0.5561), indicating a little modified D genome; (3) Ae. ventricosa (DN)
.4947), indicating a greatly modified D genome.
3 Cluster analysis
A dendrogram for the diploids was constructed based on genetic similarity indexes (Fig.
. As shown in Fig. 2, Ae. speltoides (S) and Ae. sharonensis (Ssh) were clustered together,
. longissima (Sl) and Ae. searsii (Ss) were clustered in a branch, and another branch was
mposed of Ae. bicornis (Sb), Ae. tauschii (D) and Ae. markgrafii (C). These results indicate
Acta Phytotaxonomica Sinica Vol. 44 290
Table 3 Matrix of genetic similarity for 23 accessions in Aegilops based on ISSR marker*
01 02 03 04 05 06 07 08 09 10 11
01 1.0000
02 0.5355 1.0000
03 0.4800 0.4118 1.0000
04 0.4694 0.5550 0.3825 1.0000
05 0.4545 0.4663 0.7027 0.4660 1.0000
06 0.7273 0.5389 0.4432 0.5243 0.4615 1.0000
07 0.5644 0.5584 0.3704 0.5429 0.4340 0.5943 1.0000
08 0.5543 0.5028 0.3509 0.4479 0.4330 0.4948 0.5758 1.0
09 0.5600 0.5333 0.4492 0.5192 0.4952 0.5143 0.5794 0.6
10 0.5257 0.5176 0.3457 0.4809 0.3676 0.4973 0.5608 0.7251 0.5668 1.0000
11 0.4677 0.4898 0.3936 0.4306 0.4455 0.4834 0.5395 0.5 9 1.0000
12 0.5763 0.5116 0.4024 0.4649 0.4171 0.5561 0.4921 0.5 8 0.4842
13 0.5333 0.4686 0.3473 0.4681 0.3684 0.4947 0.4948 0.5 9 0.4870
14 0.6032 0.5217 0.4318 0.4873 0.4724 0.6533 0.6995 0.5 0 0.5347
15 0.5773 0.5185 0.3867 0.4257 0.4216 0.5588 0.5769 0.6
16 0.5000 0.5829 0.3713 0.4362 0.4211 0.5158 0.5258 0.6
17 0.4767 0.5269 0.4151 0.4333 0.4396 0.4725 0.4624 0.5
18 0.4713 0.5207 0.3727 0.4396 0.4239 0.4783 0.5319 0.6
19 0.5778 0.5143 0.3832 0.4255 0.4105 0.5579 0.5979 0.6
20 0.5761 0.5922 0.3860 0.4896 0.4433 0.5155 0.5556 0.6
21 0.5355 0.4944 0.3882 0.4293 0.4456 0.4870 0.5279 0.6
22 0.5792 0.5393 0.4235 0.3979 0.4870 0.5803 0.5482 0.5
23 0.6077 0.5455 0.4286 0.4444 0.4712 0.6073 0.5333 0.5
* The accession numbers of materials are the same as those stated in Table 1.

















0.25 0.50 0.75 1.00
Similarity coefficient
Fig. 2. UPGMA dendrogram based on genetic similarity for 11 diploids (with the g
genus Aegilops. Similarity coefficient was given on scale below the dendrogram.
381 0.5352 0.531
202 0.5291 0.548
114 0.5625 0.574
405 0.5473 0.625A
A
A
A
A


000
224 1.0000 842 0.5825 0.7403 0.5894
364 0.5938 0.6347 0.4870
833 0.5109 0.6164 0.4432
0.4706
0.5389 000 0.5054 0.5839
932 0.5938 0.6826
444 0.5816 0.6433 0.5076
257 0.5744 0.6000 0.4592
922 0.5641 0.5412 0.4796
424 0.5803 0.5476 0.4845
e. bicornis (Sb)
e. tauschii (D)
e. markgrafii (C)
Ae. umbellulata (U)
Ae. comosa (M)
Ae. uniaristata (N)
Ae. heldreichii (Mh)
e. speltoides (S)
e. sharonensis (Ssh)
Ae. longissima (Sl)
Ae. searsii (Ss)


enomes listed in the brackets) in the
No. 3 GONG Han-Yu et al.：Genomic evolutionary changes in Aegilops allopolyploids 291

12 13 14 15 16 17 18 19 20 21 22 23











1.0000
0.5325 1.0000
0.6180 0.5635 1.0000
0.5792 0.5806 0.6769 1.0000
0.6272 0.5465 0.5635 0.6129 1.0000
0.6460 0.5488 0.5780 0.5843 0.6951 1.0000
0.5767 0.4578 0.5714 0.6000 0.6506 0.5570 1.0000
0.5680 0.5581 0.6298 0.7742 0.6395 0.6098 0.6506 1.0000
0.5665 0.5227 0.5622 0.6526 0.6591 0.5833 0.6471 0.7386 1.0000
0.5698 0.5600 0.5652 0.6138 0.6514 0.6108 0.6509 0.6743 0.7821 1.0000
0.6628 0.5143 0.6196 0.5926 0.5829 0.5749 0.5917 0.6629 0.6480 0.6292 1.0000
0.6706 0.5318 0.6484 0.6203 0.5665 0.5697 0.6228 0.6590 0.6215 0.6364 0.8977 1.0000


that S genome and its subgenomes had diverged through the long evolutionary process. In
addition, Ae. umbellulata (U), Ae. comosa (M) and Ae. uniaristata (N) were clustered in a
group, indicating that the genomic constituents of these three diploid species were similar. Ae.
heldreichii (Mh) showed distinct alterations and differed evolutionary directions from Ae.
comosa (M).
The dendrogram for the polyploids and their ancestral diploids is shown in Fig. 3. All
polyploid genomes that contained genome U were clustered into a large group, indicating that
genome U had changed little while others had changed significantly from the time when the
U-containing polyploids were formed. Additionally, all D-containing genomes were clustered
into different groups, suggesting that the constituents of genome D had variable degrees of
changes after polyploidization.
An interesting phenomenon was observed from the dendrogram: Ae. columnaris (UM),
Ae. biuncialis (UM), and Ae. ovata (UM) belonged to different groups, indicating that UM
genome had undergone a little alteration and had different evolutionary directions.
3 Discussion
3.1 Genome U was relatively conservative compared with other genomes in U-contain-
ing allopolyploids
Polyploidy has long been recognized as a prominent speciation process in plants (Leitch
& Bennett, 1997). Polyploid evolution appears to be more of an ongoing, dynamic process in
plants than in most other eukaryotes (Wendel, 2000; Yang, 2001). In the genus Aegilops,
genome U may have played an important role in polyploid evolution (Zohary & Feldman,
Acta Phytotaxonomica Sinica Vol. 44 292














Fig. 3. UPGMA dendrogram based on genetic similarity for 12 polyploids and their ancestral diploids (with the genomes
listed in the brackets) in the genus Aegilops. Similarity coefficient was given on scale below the dendrogram.
Ae. markgrafii (C)
Ae. bicornis (Sb)
Ae. tauschii (D)

Ae. sharonensis (Ssh)
Ae. longissima (Sl)
Ae. searsii (Ss)
Ae. heldreichii (Mh)
Ae. speltoides (S)
0.25 0.50 0.75 1.00
Similarity coefficient
Ae. cylindrica (DC)
Ae. umbellulata (U)
Ae. comosa (M)
Ae. triuncialis (UC)
Ae. biuncialis (UM)
Ae. ovata (UM)
Ae. triaristata (UMN)
Ae. columnaris (UM)
A
Ae. juvenalis (DMU)
Ae. vavilovii (DMS)
Ae. uniaristata (N)
Ae. ventricosa (DN)


1962). Our data have shown that almost all U-containing genomes were clustered into a large
group (Fig. 3), indicating that genome U was relatively cons wed little
alterations. For example, Ae. kotschyi (US) and Ae. peregrina (U ilar to Ae.
umbellulata (U) than to Ae. searsii (Ss) although Ae. searsii (Ss) w ic donor
(Terachi et al., 1990). The present study supports the pivotal-dif
by Zohary and Feldman (1962). According to the U genome e
our study, we thought that when one or more alien genomes en
they would be modified in order to accommodate the new cy
genome U, and genome U generally exerted assimilating effec
phenomenon was observed in the genus Brassica. Genome B is
polyploid Brassica carinata (BC) and B. juncea (AB) (Liu
phenomenon could be initiated by intergenomic recombination (Servative and sho
S) were more sim
as their cytoplasm
proposed
bserved in
e nucleus
ment and rential hypothesis
tionary pattern o
ered into the sam
toplasmic environ A similar
tive in the relatively conservat
volufe t on other genomes.Ae. crassa (DM) Ae. kotschyi (US) e. peregrina (US) et al., 2003). The above
ong et al., 1995), rapid and
No. 3 GONG Han-Yu et al.：Genomic evolutionary changes in Aegilops allopolyploids 293
programmed sequence elimination of low-copy sequences (Feldman et al., 1997; Shaked et
al., 2001; Liu et al., 2002), reciprocal intergenomic invasion by repeats (Belyayev et al.,
2000), DNA methylation changes (Comai, 2000; Lee & Chen, 2001), gene conversion, and/or
other homologous genetic interaction, such as mutations, and transposable element activities
(Liu & Wendel, 2002).
3.2 Genome UM had undergone genomic changes
The three tetraploid species carrying UM genome were clustered into different groups
and showed differential evolutionary directions (Fig. 3). This evolution was probably due to
mutations in regions flanking some of the microsatellites. In some cases, insertions/deletions
and base substitutions in microsatellite flanking regions were responsible for polymorphisms
in polyploids (Buteler et al., 1999; Zhang et al., 2004). Sequence analysis of several
microsatellite alleles from hexaploid Ipomoea batatas (L.) Lam., tetraploid I. Trifida G. Don,
and diploid I. trifida have suggested that complex genetic mechanisms are responsible for
microsatellite allelic variation (Buteler et al., 1999). Changes in allele size involving an
increase or decrease in multiples of the dinucleotide repeat fit a simple stepwise mutation
model with strand slippage during replication as the most likely molecular mechanism (Strand
et al., 1993).
3.3 Genome D possessed a volatile nature and showed variable degrees of alterations
As shown in Fig. 3, the genome D in different polyploid genomes had also changed to
varying degrees after polyploidization, which supports the hypothesis that the D-genome
cluster did not show a classic pivotal-differential pattern of evolution because genome D also
presented increasing levels of differentiation (Kimber & Sears, 1987). This suggests that the
intergenomic action between genome D and other genomes were distinct in polyploids. It
seemed that genome D had undergone differentiation recently, because the three D-containing
species were still clustered into a group although the others belonged to different groups.
3.4 Some maternal genomes also displayed significant alterations in allopolyploids
Song et al. (1995) observed that paternal genomes showed more alterations than maternal
genomes in the genus Brassica polyploids, and considered that this result is attributed to the
actions of maternal cytoplasm. Our data indicate otherwise: Some maternal genomes
displayed more alterations than paternal genomes in allopolyploids of Aegilops. These
genomes could be divided into two groups: the first was composed of Ae. kotschyi (US) and
Ae. peregrina (US), while Ae. cylindrica (DC) and Ae. ventricosa (DN) constituted the
second. According to the studies of Terachi et al. (1990), Ae. searsii (Ss) and Ae. tauschii (D)
were cytoplasmic donors for the two groups respectively. Our results indicate that a plausible
grouping mechanism for the first group was the assimilating effect of genome U (see
discussions above). In the second group, Ae. cylindrica (DC) was more similar to Ae.
markgrafii (C) than to Ae. tauschii (D) (Fig. 3), which was consistent with the results of the
evolution of ITS regions in Aegilops allopolyploids (Wang et al., 2000). Additionally,
genomes D, C and N were clustered into a large group (Fig. 2), suggesting that they had close
genetic relations and probably possessed a high level of compatibility. These, taken together,
suggest that when battling the nuclear-cytoplasmic interaction in a new cytoplasmic
environment, little change was needed for genomes C and N, and it was easy for them to
adapt with genome D. Another possible reason was that based on ISSR data, genome D
presented increasing levels of differentiation (Kimber & Sears, 1987), so it might show
evolutionary alterations at the genomic sequence level.
Acknowledgements We thank Dr. Taihachi Kawahara (Kyoto University) and Dr. Xinming
Yang (Chinese Academy of Agricultural Sciences) for supplying the seeds.
Acta Phytotaxonomica Sinica Vol. 44 294
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山羊草属异源多倍体植物基因组进化的 ISSR分析
龚汉雨 刘爱华 王建波*
（武汉大学生命科学学院植物发育生物学教育部重点实验室 武汉 430072）

摘要 使用31个ISSR引物对山羊草属Aegilops多倍体植物及其祖先二倍体(共23种)的基因组进行了分
析, 结果表明: 与其二倍体祖先种相比, 异源多倍体物种的基因组发生了很大变化。在含U基因组的异
源多倍体物种中, U基因组相对而言变化很小, 而其他基因组则发生了不同程度的变化。这表明当U基
因组与其他基因组共存于多倍体物种中时, U基因组表现出较强的“同化效应”。对这些基因组的进化
进行了讨论。
关键词 山羊草属; 异源多倍体; 基因组进化; ISSR